The risks of using hypnosis for change are roughly the same as those for other forms of psychotherapy. Competently performed hypnosis in itself has virtually no risk or danger. Even incompetently performed hypnosis usually has only a very minimal risk. Skillfully utilized suggestion by a malicious or unethical hypnotist, or hypnosis used with a particularly vulnerable person has some possible real psychological dangers associated.

Hypnotists in the process of psychotherapy (hypnotherapy) sometimes momentarily lose control during hypnosis because they encounter psychological needs or problems in their clients that catch them by surprise. If they are not well trained to deal with such events, there is a possible risk of exacerbating existing problems, or a remote chance of creating new problems. Hypnosis often involves vivid imagery which seems very real to the client, and intense emotion which is very real to the client. The hypnotist may even get caught up in the fantasy, or at least the emotion of it. One leading medical hypnotist (Meares, 1961) listed the following potential areas of difficulty that the untrained or poorly trained hypnotist may confront, most of which are common to all forms of psychotherapy :

1. The situation may be deliberately misused to meet ulterior needs (e.g. seduction of trusting female clients)
2. The interaction may enhance negative aspects of the hypnotist's personality, or create dependence of the client on the hypnotist
3. Traumatic confrontation with previously unacknowledged memories
4. Precipitation of a latent psychosis
5. Substitution of one symptom for another
6. Panic reaction, or creation of traumatic fantasy
7. Complications due to misunderstandings
8. Difficulty in arousing the client, and problems caused by incomplete alerting.

The last category is an interesting example, because it is unique to hypnosis, and sounds like the sometimes voiced fear of "getting stuck in a trance." The media inspired scenario is that the hypnotist dies during hypnosis and their client never wakes up because they never get the commands to awaken.

No, you can't possibly get stuck in a hypnotic trance. However, a hypnotist can (rarely) get stuck trying to end a hypnosis session ! This is not because the client has lost control of hypnosis, but because the hypnotist has lost control to the client, who has decided that they need to stay "out of it" for a while longer. The same principle applies to most problems infrequently encountered in hypnosis. The client, for their own reasons, is exercising their own control over the situation, their own psychological needs are coming to the surface.

The hypnotic "trance" is passive simply because hypnotized people find it more comfortable to remain still, not because they are immobilized by forces outside their control. They are fully capable of waking at any time, or moving at any time, if they are uncomfortable with what the hypnotist is suggesting to them. Hypnotized people do what they feel they need to do at the moment, which usually means cooperating with the hypnotist. However, this cooperation, or trust, can be broken during hypnosis, without ending the hypnotic session. The relaxed state of passivity will remain as long as the client is comfortable with it.

Hypnotic trance, like all "states of consciousness" is not turned on and off as if by a switch, it is a dynamic experience maintained by a number of continuously changing psychological and physiological variables. Left alone, without instructions to end hypnosis, we naturally either rouse fully or fall asleep. Like other psychological states, hypnotic trance varies continuously over time due to changing physiological and psychological factors.

What of the valid concern that it may be temporarily difficult to alert someone from hypnosis ? I say temporarily, although this has been reported to last as long as 12 days (Williams, 1953). It is important for the hypnotist to realize that that their client is attempting to control their own behavior. Understanding the reason for this kind of defensive reaction may be a key step in their therapy.

For those interested, a good list of "horror stories" about dangers in hypnosis is available (MacHovec,1986). Robert Baker ("They Call It Hypnosis") calls MacHovec's book "a collection of cases of individuals who suffered from various sorts of personality and emotional disorders prior to hypnotherapy, and then after hypnotherapy blamed the therapy for their problems." The object lesson here seems to be that hypnosis is safe when the hypnotist is properly trained to deal with the problem at hand. To help people recover from bad habits or improve their golf swing requires less specialized psychological training than dealing with more acute problems.

Even a safe procedure like hypnosis can help precipitate a serious problem in some people, if used for generally psychotherapy without adequate knowledge of both psychotherapy and hypnosis (Frauman, Lynn, & Brentar, 1993; Kleinhauz & Eli, 1987; Judd, Burrows, Dennerstein, 1985; Kleinhauz & Beran, 1984; Orne, 1965; Rosen, 1957; Rosen & Bartemeier, 1961).

Clinical data on hundreds of inductions gathered by E.R. Hilgard showed that hypnosis is a safe procedure, and that there are virtually no negative consequences associated specifically with hypnosis (Hilgard, Hilgard, & Newman, 1961). The only adverse effects found were temporary headaches or discomfort reactions upon attempting induction. These seemed to be correlated with previous negative experiences with general anesthesia.

In spite of the safety of hypnotic induction, there are strong psychological forces at work during therapy that must be respected when hypnosis is used as a tool for change. If an unexpected situation is encountered, and the hypnotist panics or behaves irresponsibly, there is a very real risk in some cases of existing psychological problems becoming exacerbated. Several years later, Hilgard added that :

"On the whole, hypnosis is not at all dangerous ... Still, there are some people who have a very slight hold on reality and for whom too much playing with fantasy might conceivably release tendencies toward psychotic behavior that they have shown under other circumstances as well. If such discordant behavior follows hypnosis, the hypnotist is likely to be blamed for it, even though there can usually be found many instances of similar behavior by the subject prior to any attempted hypnosis." (Hilgard, 1971)

This is why hypnosis should not be considered a casual interaction, but an intimate communication that should be used with some respect. Just as it would be irresponsible to do other sorts of psychotherapy without training, hypnosis used irresponsibly can have unexpected and even unfortunate results with people who already have underlying serious problems (Coe and Ryken, 1979) (Hilgard, 1974). Since these sorts of problems sometimes go undiagnosed for years, they sometimes arise quite surprisingly in therapy.

The general rule is : don't let someone treat something with hypnosis, if they aren't qualified to treat it without hypnosis. In other words, training in hypnosis alone does not qualify someone to treat psychological problems. Treating psychological problems involves inherent risk, and the capacity of hypnosis to reproduce a variety of psychological conditions makes it possible that a hypnotist can trigger a problem that they never suspected exists